Asphalt-coated sheet-metal pipe



(No Mdel.)

J. P. CULVBR.

ASPHALT COATED SHEET METAL PIPE. No. 400,832. PatentedlApr. 2, 1889.

UNITED STATES PATENT f OFFICE.

JOHN P. OULVER, OF LOS ANGELES, CALIFORNIA.

ASPHALT-COATED SHEET-METALPIPE.

SPECIFCATION forming part of Letters Patent N0. 400,832, dated April 2, 1889.

Application filed December 14, 1888. Serial No. 293,584. (No model.)

To all Ztl/"1,0m it may concern:

Be it known that I, JOHN P. OULVER, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Riveted Multiple Asphalted Sheet- Metal Pipe, ot' which the following is a speciication.

My invention relates to improvements in that class of pipe composed of a thin sheet of iron or other suitable metal wrapped upon itself and having a coating of asphaltum or other suitable cementing and protecting substance interposed between the layers of the sheet metal.

It is desirable in pipe of this class that the sections be made of a greater length than can be readily and cheaply riveted; and my invention relates more particularly to the riveting of the free edge of the sheet along the portions of the pipe which cannot be readily reached from the ends in riveting. Itis also desirable that such pipe be made of a slightly greater diameter at one end than at the other, so that the several joints may be iitted into each other.

One object of my invention is to produce a strong, light, durable, and cheap pipe suitable for water, gas, and sewer pipes.

A further object is to provide cheap and et'cient means for securing the free edges of convolute sheet-metal pipes.

My invention consists of a pipe comprising a convolute sheet of metal coated throughout its entire extent with asphaltum or other protective cementing substance, and having its free edge secured wholly or in part by means of rivets passing through the several thicknesses of metal and cementing substance.

It consists more particularly of such pipe having the free edge of the sheet secured by rivets of metal cast within the rivet-holes and suitable molds for forming the heads of the rivets.

The drawings illustrate my invention and the device for casting the rivets.

Figure 1 is a view of a section of pipe showing the convolute sheet of metal secured by rivets. Fig. 2 is a longitudinal section through the line of rivets. The thickness of the sheet and the asphaltum are exaggerated. This view also shows a portion of the mandrel within the pipe. It also shows a molding-cup set on the top of the pipe to form the set-head of the rivet to be cast.

In manufacturing the pipe the sheet of metal A, coated wit-h asphaltum or oth er suit able cementing and protecting substance and wrapped convolute upon itself, is placed upon a mandrel, B, provided upon its upper side with a hole, O, through which the punch-chip may pass down through the mandrel. A dieplate, D, is fitted into the mandrel. This dieplate is interchangeable, so that new dieplates may be substituted for worn ones. Another hole, E, is provided in the top of the mandrel at the distance from the hole C corresponding to the space desired between the rivets. This hole is larger in cross-section than the cross-section of the rivet desired and is intended to form a mold for the inner head of the rivet. G are the rivets.

H is the mold-cup for forming thc outer or set head of the rivet.

Vhen the sheet of metal is properly Wrapped and pressed iirmly together, it will maintain its shape and sustain great pressure without being riveted 5 but when roughly handled, o1' when subjected to heat, the outer lap or edge of the sheetisliable to become loosened. 'The object of the rivets is to hold the edge of the sheet in place. The bursting-strain upon the pipe is largely sustained by the fold of the sheet, so that the fastening for the edge of the sheet need not be very strong.

When the pipe has been made as above described, l place the pipe upon the mandrel so that the punch-hole O will be under the point desired for the middle rivet, and a hole is punched with a proper die. Then the pipe is drawn oit of the mandrel until the rivethole punched centers with the hole E. Then the mold-cup H is iitted over the rivetfhole and molten metal is poured therein, thus forming a rivet. The next hole is then punched, and the operation just described is continued until the rivets are set to the end of the pipe. Then the pipe is reversed and the rivets cast in the other end in the same manner. If desired, ordinary rivets may be placed at the IOO ends of the pipes in the manner now in co1nmon use. I have discovered that rivets formed of easily-fusible metal-such as alloys of zine and lead, daer-are suioiently strong enough for this purpose. By this means I ain enabled to rivet the pipe throughout its entire length at a very slight expense. If desired, two or more rows of rivets may be used. The hole E in the mandrel and the hole .I in the moldcup H form suitable molds for the heads of the rivets. L represents the asphaltum or other cement-ing substance. By this construction of pipe very thin iron can be used with two or more laps, thus making a strong pipe thin enough to allow the ends to be fitted into each other, thus dispensing with the collars ordinarily used to forni the joints.

Now, havin g described my invention, what I holes, as described.

JOHN P. CULVER. Witnesses:

JAMES R. TowNsEND, M. C. GALER. 

